The invention relates to a clamping device, such as for example a swing clamp, a machine vice, a support element or a block cylinder. Clamping devices of this type are for example known from DE 102 05 601 A1, DE 102 52 549 A1, DE 33 34 401 A1 and DE 197 52 671 A1, wherein clamping devices of this type have hitherto for the most part been driven hydraulically and have position sensors which determine the position (clamped or unclamped) of the clamping device. Furthermore, it is known from the prior art to drive clamping devices of this type by means of an electric motor, wherein hitherto position sensors were however likewise used in order to determine the position (clamped resp. unclamped) of the clamping device.
The disadvantage of these known clamping devices is therefore the fact that separate position sensors are necessary for determining the position (clamped resp. unclamped).
A clamping device is known from DE 195 17 345 A1, in which the clamping element is driven by an electric motor. Here, the clamping force of the clamping device can be calculated from the torque and thus from the current consumption of the electric motor. The electric motor can then be switched off if the current consumption reaches a certain predetermined value, which corresponds to the desired clamping force. This method requires, however, a very precise and dynamic measurement of the current consumption.
Reference is also to be made to DE 10 2010 044 783 A1, DE 36 38 526 C1 and DE 30 31 368 A1 concerning the prior art.
The object of the invention is therefore to improve the known clamping devices accordingly.
This object is achieved by means of a clamping device according to the invention and by means of a corresponding operating method.